Energy absorbing and sizing means for helmets

ABSTRACT

A system for absorbing energy to avoid the detrimental effects of impacts in protective equipment such as helmets comprising a plurality of first chambers located on the inside surface of the helmet for positioning adjacent the head of the wearer. A substantially non-compressible fluid is included within these first chambers, and conduits connect the first chambers with corresponding second chambers. Upon impact, fluid is displaced to the second chambers, and, due to the design of the chambers, the displaced fluid is returned to the first chambers when the force of the impact is removed. Sizing means useful with the energy absorbing means or in other applications are located on the interior of the helmet surface. The sizing means include expandable compartments, and valves are associated with these compartments whereby a user of the helmet can place the helmet on his head after which air is introduced into the compartments until a proper fit is achieved. Energy absorbing pads are preferably located within the compartments to serve as additional safeguards under high impact conditions.

United States Patent [19.]

Margan [54] ENERGY ABSORBING AND SIZING MEANS FOR HELMETS [75] inventor: Gerard E. Margan, Lake Forest, ill.

[73] Assignee: Riddell, lnc., Des Plaines, Ill.

[22] Filed: July 27, 1970 [2]] Appl. No.: $8,462

Related U.S. Application Data [60] Division of Ser. No. 808,800, March 20, i969, which is a continuation-in-part of Ser. Nos. 457,0l6, May 19, 1965, abandoned, and Ser. No. 664,748, Aug. 31, 1967, abandoned.

[52] U.S. Cl ..267/ll7 [51] Int. Cl. ..F16t 9/10 [58] Field of Search ..269/1 17; 206/46 [56] References Cited UNITED STATES PATENTS 2,577,274 l2/l95l Sampson ..267/l 17 2,434,641 1/1948 Burns ..267/l 17 Primary ExaminerJames B. Marbert Attorney-McDougall, Hersh & Scott Jan. 30, 1973 [57] ABSTRACT A system for absorbing energy to avoid the detrimental effects of impacts in protective equipment such as helmets comprising a plurality of first chambers located on the inside surface of the helmet for positioning adjacent the head of the wearer. A substantially non-compressible fluid is included within these first chambers, and conduits connect the first chambers with corresponding second chambers. Upon impact, fluid is displaced to the second chambers, and, due to the design of the chambers, the displaced fluid is returned to the first chambers when the force of the impact is removed.

Sizing means useful with the energy absorbing means or in other applications are located on the interior of the helmet surface. The sizing means include expandable compartments, and valves are associated with these compartments whereby a user of the helmet can place the helmet on his head after which air is introduced into the compartments until a proper fit is achieved. Energy absorbing pads are preferably located within the compartments to serve as additional safeguards under high impact conditions.

9 Claims, 20 Drawing Figures PATENTEU JAN 3 0 I973 SHEET 0F 4 ENERGY ABSORBING AND SIZING MEANS FOR HELMETS This is a division of my copending application Ser. No. 808,800, filed on Mar. 20, 1969, which application was a continuation-in-part of application Ser. No. 457,016, filed on May 19, 1965, and now abandoned, and application Ser. No. 664,748, filed on Aug. 31, 1967 and also now abandoned.

The invention relates primarily to improved helmet constructions although application to other types of protective equipment is contemplated. The construction particularly comprises a mechanism adapted to be employed for receiving impact forces and for dissipating the forces to thereby materially reduce the adverse affects of the impact. In addition, the construction includes a sizing means which permits adaptation of the same helmet to a variety of individuals and which cooperates in an ideal fashion with the energy absorbing means.

A wide variety of helmet structures have been designed for absorbing energy since there are many circumstances where individuals are susceptible to impact forces which could result in serious head injuries. In certain instances, the forces arise when the head strikes a more or less stationary object such as a wall or an automobile dashboards. In other instances, the forces arise due to impact which results when another object moves into contact with the individual. This may occur in contact sports such as football, or the impact forces could result when workmen are struck by falling objects.

In addition to energy absorbing means, a proper fit is also of critical importance in helmet constructions. Provision is made for fitting by providing a head cradle, usually composed of a plurality of straps, along with some means for adjusting the straps. This is, however, somewhat unsatisfactory since completely accurate adjustments are difficult to make, and since the adjustments can not be made while the helmet is on the head.

Since an improper fit can result in serious injury, it has been necessary for helmet manufacturers to make available a complete range of sizes of helmets. This leads to additional costs both from the standpoint of manufacturing and due to the fact that users of the helmets must secure large inventories in order to accommodate different individuals and to permit immediate replacement.

It is a general object of this invention to provide a novel design for a construction used for protection against impact forces.

It is a more particular object of this invention to provide a construction which involves the use of liquids or other substantially non-compressible fluids for the pur pose of dissipating energy which results from impact forces.

It is a still further object ofthis invention to provide constructions of the type described which are adapted to be readily associated with helmets whereby individuals can be protected against the adverse affects of impact in a highly effective manner.

It is a still further object of this invention to provide an improved sizing means for helmets whereby accurate fitting of a helmet can be accomplished and whereby the need for a large inventory of different helmet sizes can be minimized or eliminated.

These and other objects of this invention will appear hereinafter and for purposes of illustration, but not of limitation, specific embodiments of this invention are shown in the accompanying drawings in which:

FIG. 1 is a vertical, sectional view of a helmet construction provided with energy absorbing and sizing means characterized by the features of this invention;

FIG. 2 is a vertical, sectional view of the helmet construction taken about the line 2--2 of FIG. 1;

FIG. 3 is an enlarged fragmentary, sectional view of an energy absorbing element utilized in the construction;

FIG. 4 is.a vertical sectional view taken about the line 4-4 of FIG. 1;

FIG. 5 is a plan view of an inflating means which can be used with the construction of the invention;

FIG. 6 is a bottom plan view of the helmet construction;

FIG. 7 is a schematic illustration of the construction as it is placed on a persons head;

FIG. 8 is a plan view of a sizing means assembly for location at the crown and sides of the helmet;

FIG. 9 is a plan view of an assembly of energy absorbing and sizing means for location in the front of the helmet;

FIG. 10 is a plan view of an assembly of energy absorbing and sizing means for location at the back and neck areas of the helmet;

FIG. 11 is an enlarged crosssectional view, taken about the line 11-11 of FIG. 8, illustrating the valve means utilized in the construction;

FIG. 12 is an enlarged fragmentary, sectional view illustrating a snap-in stud construction utilized for securing the energy absorbing and sizing means in the construction;

FIG. 13 is a perspective view of an alternative design of sizing means;

FIG. 14 is an enlarged fragmentary, sectional view illustrating an alternative form of valve mounting means;

FIG. 15 is an enlarged fragmentary sectional view illustrating an alternative form of fastener means for securing energy absorbing and sizing assemblies;

FIG. 16 is an enlarged fragmentary sectional view illustrating an additional type of sizing means;

FIG. 17 is a cross-sectional view illustrating an alternative form of energy absorbing means;

FIG. 18 is a detailed, fragmentary, cross-sectional view illustrating the operation of the construction of FIG. 17;

FIG. 19 is a cross-sectional view illustrating schematically the energy absorbing capabilities of the construction; and,

FIG. 20 is a diagrammatic illustration of an additional type of energy absorbing means.

The helmet construction of this invention includes means adapted to absorb energy upon being subjected to impact. The invention provides for the use of first and second chambers which are flexible in nature in the sense that the interiors of the chambers are adapted to increase and reduce in size in response to the application and removal of impact forces.

A passagemeans is provided for interconnecting the respective chambers, and a substantially non-compressible fluid is included in the first chamber. When an impact force is applied, the fluid is adapted to be transferred from the first chamber to the second chamber through the passage means. The work involved in moving the fluid represents a direct measure of the amount of energy absorbed. By providing an appropriate design for the energy absorbing means to fit their location in the helmet, the energy absorption capabilities will be such that injury or damage can be eliminated or reduced to a desirable minimum.

The sizing means of this invention generally consist of a plurality of air compartments situated over the interior surface of the helmet shell. Valve means accessible from the exterior of the shell are provided for inflating the compartments whereby the helmet can be fit while in place on an individuals head. Additional energy absorbing means are preferably included within the compartments to provide a back-up in the event of especially high impact or in the event of failure of the primary energy absorbing means.

In a preferred form of the invention, the combination of the energy absorbing and sizing means is used together, preferably by placing these means on a liner which fits within the helmet shell. With this combination, assembly of the helmet can be accomplished in an extremely efficient manner. Fastening means for the liner and air valves are designed to that additional safety features are provided.

FIGS. 1, 2, 4 and 6 illustrate a helmet 10 provided with the energy absorbing and sizing means. The energy absorbing means are in the form of elements 12 including first and second chambers 14 and 16. The sizing means with associated energy absorbing means include a first set 18 for engaging the back of the neck, a second set 20 positioned to engage an intermediate area at the back of the head, a third set 22 extending over the front of the head and a crown and side set 24.

As shown in FIGS. 8-10, common backing sheets 25 may be provided for the energy absorbing and sizing means. These backing sheets are individually attached to the helmet shell which is preferably formed of a relatively rigid material such as hard plastic, metal, or the like.

Each of the energy absorbing means carries a noncompressible fluid, the major portion of which is present in the larger chambers 14. Each chamber 14 communicates with a chamber 16 through constricted passage 26. Accordingly, when force is applied to the energy absorbing means, fluid is adapted to be transferred from the chamber 14 to the chamber 16.

The energy absorbing means 12 are formed of a flexible material which can be sealed to form fluid-tight chambers, for example by gluing or heat sealing. Such materials provide the desired flexibility while also having characteristics which simplify manufacturing. In the embodiment shown, the energy absorbing means 12 are heat sealed directly to the backing sheet 25. (See FIG. 3). A heat seal is provided at 28 for purposes of forming the relatively narrow passage 26 between the chambers (FIGS. 9 and 10). The size of this passage will determine the amount of force required to permit transfer of fluid from a first chamber to a second chamber.

By controlling the extent of heat sealing around the chamber 16, the size of the chamber can be controlled. This chamber is designed to normally urge the fluid into the chamber 14. Accordingly, when an impact force is removed, the energy absorbing elements will resume their normal configuration. As explained in the aforementioned copending applications, independent means could be provided for normally compressing the chamber 16, for example, resilient bands overlying the chamber 16. It is essential to the operation of the coristruction, however, that the fluid be preferentially included within one chamber for transfer to the other chamber upon the application of force. Substantially all of the fluid should, therefore, be in the chamber 14 with only a minimum amount of fluid, if any, being present in the chamber 16 until a force is applied.

The energy absorbing members 12 are located at strategic points over the interior wall of the construction. Obviously, the location of the energy absorbing means should be such that protection will be provided irrespective of the direction of impact.

The sizing means of this invention each comprise a compartment 32 or a compartment 24' in the case of the crown (FIGS. 8-10). These compartments are located in spaced apart relationship over the interior surface of the helmet. The location of the compartments is selected so that upon inflation of the compartments, the helmet shell will be evenly spaced apart as much as possible with respect to the head of the wearer.

The sizing compartments can be manufactured by locating a flexible material on backing sheet 25 and then sealing off the compartment, for example, by heat sealing or gluing. In the embodiment illustrated, the material is heat sealed to the backing sheet around all edges of each compartment with the exception of small passages 36 which interconnect the respective compartments. This arrangement is best illustrated in FIGS. 9 and 10.

A valve 38 may be associated with each compartment or set of compartments. Referring to the sets 18, 20 and 22 in FIGS. 9 and 10, it will be noted that a valve is associated with the intermediate compartment, and due to the interconnecting passages 36, all of the compartments 32 can be filled with air simultaneously. In the case of any set, a single valve can be employed; however, two or more valves could be positioned at intervals particularly where greater numbers of compartments are included in a set.

In FIG. 8, the set 24 consists of a compartment 24' of circular configuration with a valve 38 communicating with the interior of this sizing means. This compartment 24 is situated in the crown of the helmet for engaging the top of the wearers head. A bellows type body may alternatively be used for the compartment or for others of the sizing means.

A second valve means 38 associated with this assembly communicates with a bubble 41 which, in turn, is connected through the passages 41 to the side compartments 32. As will be explained, these side compartments are provided with a separate valve so that they can be inflated separately from the chamber 24 during the fitting operation.

The backing sheets 25 for each of the configurations shown in FIGS. 8-10 are provided with tabs 43. These tabs define openings 45 for alignment with corresponding openings in securing bands 47. These securing bands comprise relatively stiff plastic pieces which are secured to the helmet wall by means of snap-in studs 49 shown in FIG. 12. The studs 49 include an enlarged bifurcated end 49' which, when pressed into reduced diameter openings in the helmet shell, will hold the bands in a secure position. As best shown in FIG. 1, the openings in the helmet shell define a counter sunk portion 49" so that the enlarged end 49' will lock into place.

The sets of energy absorbing and sizing means can be riveted or otherwise attached to the bands and the bands are then secured to the helmet shell by means of the snap-in studs 49. The valves 38 are attached to the sizing chamber assemblies prior to attachment of these assemblies to the bands, and the valves are then adapted to be snapped into place relative to the helmet shell.

A preferred construction for the valves 38 is shown in FIG. 11. The valves comprise a beaded inner end 140 whereby a resilient band 142 can be held in place around the valve body. The valve is slit at 144, and a central bore 146 is formed adjacent this slit. Outwardly extending shoulders 148 are provided so that the valves can be snapped into openings 150 defined by the helmet shell (FIG. 1).

The slit 144 is provided in the valve for entry of the needle 152 of the inflating means 154 shown in FIG. 5. The inflating device of FIG. 5 is merely illustrative of a suitable manually held construction; however, other conventional means can obviously be employed for this purpose. The inflating means should, however, include a needle portion which can be inserted in the bore 146 of the valve and forced through the slit in opposition to the resilient action of the band 142. The sizing means can then be inflated in a desired degree while the helmet is on the wearers head, and when the needle is pulled out, the band 142 will provide automatic sealing.

The use of studs 49 and valves 38 is particularly desirable for athletic helmets. The snap-in characteristics permit secure attachment of these members without having any protruding portions so that a smooth exterior can be provided to minimize the possibility of injuries.

A strip 53 of leather (FIG. 7) may be provided over the compartments 32 located at the front of the helmet for positioning against the forehead. This strip of 5 material serves as a sweatband, and it is preferably adhesively applied to permit easy removal and replacement.

Although sequence variations are contemplated, particularly where the design of the individual sets varies, fitting a helmet on the head of an individual, may commence with the compartment 24' of the crown area 90 (FIG. 7) being inflated first to provide a comfortable position of the helmet, for example from the standpoint of vision. The sets 22 and of compartments 32 in the areas 92 and 94 can then be inflated (preferably in that order) to provide substantially uniform spacing between the helmet wall and the front and back of the head. The set 18 is then inflated to engage the neck properly.

The side compartments 32 of the set 24 are then inflated last to complete fitting of the helmet, again without disturbing the position established by the initial inflation. It will be appreciated that the order of inflation described represents a convenient and efficient arrangement but that other inflating sequences are clearly available.

Each of the compartments preferably includes an energy absorbing element in its interior. These elements comprise a first layer formed of standard resilient material, such as expanded vinyl, used for the padding of athletic equipment. The other layer 51 is preferably a crushable material capable of absorbing energy, for example, expanded polystyrene beads sold under the trademark Ethafoam.

FIGS. 17 and 18 illustrate an alternative design for the energyabsorbing means 12 comprising a single housing 86 defining a first chamber 88 and a second chamber 90. The passages 92 and 94 interconnect the respective chambers. A first flap valve 97 permits fluid in the chamber 88 to pass into the chamber while the flap valve 98 provides for reverse movement.

A suitable resilient means may be associated with the arrangement of FIG. 17 for compressing the housing 86 in the area of the chamber 90 as suggested by the dotted lines. These compressing means will, therefore, resist entry of fluid in the chamber 90 while operating to urge return of the fluid through the passage 94.

The arrangement shown in FIGS. 17 and 18 differs from the energy absorbing means 12 primarily because of the ability of the flap valve 97 to provide for substantial changes in the size of the passage communicating the first and second chambers. Thus, in the case of the passage 26, only a relatively small increase in the diameter of the passage will occur even when high impact takes place. This increase in diameter occurs because of the resilient character of the material forming the absorbing means 12.

It will be appreciated that the features of the absorbing means 12 and 86 could be combined whereby a single passage means, having' expansion characteristics, will be provided. For example, the passage means 100 shown in FIG. 20 comprises a conically shaped tubular member having a side wall of varying thickness. The opening 101 interconnects the chambers 102 and 104 thereby providing a normally open passage for movement of fluids back and forth between the chambers. The material forming the passage is flexible so that the opening 101, being in the thin wall area, will expand by an amount depending on the size of the impact force. This is particularly important in the case of high impact, since otherwise the resistance of the chamber 102 might approach the resistance of a solid.

FIG. 19 schematically illustrates the manner in which the various elements within the construction cooperate. The sizing means 32 absorb the energy resulting from impacts of lower magnitude. In the case of a football helmet, these sizing means may absorb all the energy as much as 60 percent of the time.

When greater forces are encountered, the absorbing means 12 come into play; these absorbing means will probably be used about 30 percent of the time when utilized in football helmets. The resilient padding 50 can then be used only for the remaining l0 percent of impact forces. As shown in FIG. 19, this resilient padding may extend closely adjacent the inner surface of the sizing chamber, in which case, its effect will be utilized for lesser impact stages. Alternatively, the padding 50 may be of much lesser extent, and it will then be utilized in later stages of impact. In any event, even relatively severe impacts encountered during a football game can be readily accommodated by the three systems referred to.

The crushable material 51 is provided only for extremely severe circumstances, circumstances which might be severe enough to cause bursting of the compartments 32 and absorbing means 12. The crushable material will give under these severe circumstances and therefore may not be usable thereafter; however, since other damage has occurred; sizing means and absorbing means would have to be replaced in any event.

It will be understood that the energy absorbing means comprising the units 12 are considered to have utility apart from the sizing means, and the sizing means likewise have separate utility. Although the respective means cooperate in an ideal fashion as described, the utilization of other complementary arrangements with either of these means is contemplated.

The provision of the sizing means and the energy absorbing means on a common liner provides many advantages. Assembly is greatly simplified since accurate placement of the elements on the liner is easily accomplished. Thus, the assembly can be produced from two opposing sheets of heat scalable material with the chambers, compartments, and passages formed in one sheet. Furthermore, the liner can be easily removed in the event of any defects or failure of any of the elements on the liner. A replacement liner can be provided, and there will be no need to discard the helmet shell. Individual assemblies, for example the set 22, can be used in combination with other energy absorbing or sizing arrangements instead of using all the sets together. Finally, the energy absorbing or sizing means, or an assembly thereof, can be used with other protective equipment such as shoulder pads, jaw pads, thigh pads, hip pads, etc.

As shown in FIG. 15, a liner 52 may be provided with strap portions 54 adapted to overlap the peripheral edge of the helmet shell. By providing openings in these strap portions in alignment with openings in the helmet shell, the liner can be easily attached and removed.

One suitable means for securing the liner 52 to the helmet shell comprises a fastener 56 formed of a tough resilient material. The fastener includes an enlarged head 58, a reduced diameter shank 60, and an enlarged end 62. A narrow strip 64 is formed as an extension of the enlarged end. When the holes in the liner strap and shell are in alignment, the fastener can be forced through, and then locked in place when the enlarged end passes the last hole. The strip 64 can be grasped with the fingers to assist in forcing the fastener through the holes. By utilizing a resilient material for the fastener 56, there is a minimum danger of injury it the head should strike a fastener end.

In the arrangement shown in FIG. 16, a plate 66 is located over the interior wall of the helmet shell, and an internally threaded sleeve 68 is passed through an opening in the liner 52 and through the helmet shell. A screw 70 is then provided for securing the edge portion 54.

FIG. 14 illustrates an alternative form of valve construction. The valve comprises a shank portion 72 which extends through an opening in the helmet shell. The inner end 74 is maintained in spaced apart relationship with the helmet shell by means of a grommet 76 formed of resilient material. In the event an impact force is applied in the area of this valve, it is possible that the wearers head will actually be moved so close to the surface of the helmet shell that there is a danger of the hard valve material injuring the head. However, before this can occur, the grommet 76 will give thereby allowing the shank 72 of the valve to move outwardly of the helmet shell. The helmet constructions of this invention are, of course, designed so that the wearers head would never come into contact with a valve; howeven-the arrangement of FIG. 14 is considered desirable as a means for preventing injury in the event of failure of other components of the helmet or in the event of highly unusual impact forces.

There has been described an arrangement which provides an extremely satisfactory means for the absorbing of energy and for properly fitting a helmet. The use of liquids or any substantially non-compressible fluid in the energy absorbing means enables the absorption of energy even at extremely high levels whereby the detrimental effects of impacts can be reduced to a minimum. Relatively common liquids may be utilized, for example, an aqueous solution containing 20 percent CaC 1,. Vinyl sheets are suitable for forming the energy absorbing and sizing compartments.

The provision of air or other gas for the sizing means provides a highly effective and easily handled fitting technique. The combination of the energy absorbing means and the sizing means is itself of critical importance particularly since the design of the respective means lends itself to joint installation, for example, on a common backing, and since the highly accurate fitting cooperates with the energy absorbing means in providing a safe helmet. This latter feature is of major importance since the provision of an accurate fit, with the sizing means firmly against the head even where unusual head contours are involved, is very important in preventing head injury. Thus, if a player has a prominent knob or other unusual head characteristic, the sizing compartments will compensate to avoid any looseness.

it will be understood that various changes and modifications may be made in the above described constructions which provide the characteristics of this invention without departing from the spirit thereof particularly as defined in the following claims.

That which is claimed is:

1. An assembly comprising a plurality of interconnected fluid containing compartments mounted on a common backing, valve means communicating with said compartments for introducing and removing fluid to thereby permit changing of the size of the compartments, and energy absorbing means associated with said compartments, said energy absorbing means comprising a plurality of first flexible chambers, a plurality of second flexible chambers, passage means connecting said first chambers to said second chambers, a substantially non-compressible fluid within said first chambers, and means normally retaining said second chambers in a compressed state whereby at least a major portion of said fluid will normally be retained in said first chambers and whereby the force of an impact applied to said first chambers operates to transfer fluid through said passage means into said second chambers with said fluid moving back to the first chambers when the force is removed, and wherein combinations of first and second chambers are located on said backing between adjacent compartments.

compartments by leaving narrow unheat-sealed areas extending between the respective compartments.

3. An assembly in accordance with claim 2 wherein said second flexible chambers are provided by leaving an unheat-sealed area between substantially coextensive portions of the respective sheets whereby a minimum amount of said non-compressible fluid can be normally received in the second chambers, and wherein said first chambers are provided by heat sealing an area of one sheet of substantially greater size than the attached area of the other sheet whereby a substantially larger amount of said non-compressible fluid can be normally maintained in said first chamber.

4. in a construction adapted to absorb energy when subjected to impact, the improvement comprising a plurality of first flexible chambers positioned on the surface of the construction to receive the effects of said impact, a plurality of second flexible chambers, passage means connecting said first chambers to said second chambers, a substantially non-compressible fluid within said first chambers, said second chambers being formed by substantially overlying walls secured at their edges whereby the second chambers are normally maintained in a compressed state of low volume so that substantially all of said fluid will normally be retained in said first chambers, the force of an impact being adapted to transfer fluid through said passage means into said second chambers, and whereby the fluid transferred is moved back to the first chambers when said force is removed.

5. In an assembly for use in absorbing energy when subjected to impact, the improvement comprising a plurality of first flexible chambers adapted to receive the effects of said impact, a'plurality of second flexible chambers, passage means connecting said first chambers to said second chambers, a substantially non-compressible fluid within said first chambers, at least a major portion of said fluid normally being retained in said first chambers, the force of the impact operating to transfer fluid through said passage means into said second chambers, and whereby fluid is moved back to the first chambers when said force is dissipated, and including a plurality of sizing means attached in said assembly, and means for adjusting the size of said sizing means to permit use of the assembly under varying conditions.

6. In an assembly for use in absorbing energy when subjected to impact, the improvement comprising a plurality of sizing means, said sizing means comprising compartments having a compressible fluid disposed therein, valve means communicating with said compartments for introducing and removing said fluid to thereby permit changing of the size of said compartments, and ener y absorbing means havin ener y absorbmg capabrh res completely mdepen ent 0 said compartments and having exposed exterior surfaces for receiving applied force when impact occurs, said compartments being located at spaced intervals, and

wherein at least some of said energy absorbing means are located in spaces in said assembly defined between said compartments.

7. In an assembly for use in absorbing energy when the assembly or structure associated with the assembly is subjected to impact, the improvement comprising a plurality of flexible chambers positioned for receiving effects of said impact, a substantially non-compressible fluid normally located within said chambers, passage means extending from said chambers, fluid receiving means connected to said passage means whereby said chambers and said fluid receiving means are maintained in communication by said passage means, means for normally retaining at least a major portion of said fluid in said chambers in preference to said fluid receiving means, the force of an impact operating to transfer fluid through said passage means into said fluid receiving means, and whereby the fluid transferred is moved back to said chambers when said force is removed. I

8. An assembly in accordance with claim 7 wherein the assembly is associated with a structure comprising 

1. An assembly comprising a plurality of interconnected fluid containing compartments mounted on a common backing, valve means communicating with said compartments for introducing and removing fluid to thereby permit changing of the size of the compartments, and energy absorbing means associated with said compartments, said energy absorbing means comprising a plurality of first flexible chambers, a plurality of second flexible chambers, passage means connecting said first chambers to said second chambers, a substantially non-compressible fluid within said first chambers, and means normally retaining said second chambers in a compressed state whereby at least a major portion of said fluid will normally be retained in said first chambers and whereby the force of an impact applied to said first chambers operates to transfer fluid through said passage means into said second chambers with said fluid moving back to the first chambers when the foRce is removed, and wherein combinations of first and second chambers are located on said backing between adjacent compartments.
 1. An assembly comprising a plurality of interconnected fluid containing compartments mounted on a common backing, valve means communicating with said compartments for introducing and removing fluid to thereby permit changing of the size of the compartments, and energy absorbing means associated with said compartments, said energy absorbing means comprising a plurality of first flexible chambers, a plurality of second flexible chambers, passage means connecting said first chambers to said second chambers, a substantially non-compressible fluid within said first chambers, and means normally retaining said second chambers in a compressed state whereby at least a major portion of said fluid will normally be retained in said first chambers and whereby the force of an impact applied to said first chambers operates to transfer fluid through said passage means into said second chambers with said fluid moving back to the first chambers when the foRce is removed, and wherein combinations of first and second chambers are located on said backing between adjacent compartments.
 2. An assembly in accordance with claim 1 wherein said sizing means and energy absorbing means are formed from two opposing sheets of heat sealable material, one of said sheets providing said common backing, said sheets being heat sealed together around the peripheral edges of said compartments and around the peripheral edges of said first and second chambers, the passage means between said first and second chambers being formed by leaving a narrow unheat-sealed area between said chambers, and wherein additional passage means are provided for interconnecting said compartments by leaving narrow unheat-sealed areas extending between the respective compartments.
 3. An assembly in accordance with claim 2 wherein said second flexible chambers are provided by leaving an unheat-sealed area between substantially co-extensive portions of the respective sheets whereby a minimum amount of said non-compressible fluid can be normally received in the second chambers, and wherein said first chambers are provided by heat sealing an area of one sheet of substantially greater size than the attached area of the other sheet whereby a substantially larger amount of said non-compressible fluid can be normally maintained in said first chamber.
 4. In a construction adapted to absorb energy when subjected to impact, the improvement comprising a plurality of first flexible chambers positioned on the surface of the construction to receive the effects of said impact, a plurality of second flexible chambers, passage means connecting said first chambers to said second chambers, a substantially non-compressible fluid within said first chambers, said second chambers being formed by substantially overlying walls secured at their edges whereby the second chambers are normally maintained in a compressed state of low volume so that substantially all of said fluid will normally be retained in said first chambers, the force of an impact being adapted to transfer fluid through said passage means into said second chambers, and whereby the fluid transferred is moved back to the first chambers when said force is removed.
 5. In an assembly for use in absorbing energy when subjected to impact, the improvement comprising a plurality of first flexible chambers adapted to receive the effects of said impact, a plurality of second flexible chambers, passage means connecting said first chambers to said second chambers, a substantially non-compressible fluid within said first chambers, at least a major portion of said fluid normally being retained in said first chambers, the force of the impact operating to transfer fluid through said passage means into said second chambers, and whereby fluid is moved back to the first chambers when said force is dissipated, and including a plurality of sizing means attached in said assembly, and means for adjusting the size of said sizing means to permit use of the assembly under varying conditions.
 6. In an assembly for use in absorbing energy when subjected to impact, the improvement comprising a plurality of sizing means, said sizing means comprising compartments having a compressible fluid disposed therein, valve means communicating with said compartments for introducing and removing said fluid to thereby permit changing of the size of said compartments, and energy absorbing means having energy absorbing capabilities completely independent of said compartments and having exposed exterior surfaces for receiving applied force when impact occurs, said compartments being located at spaced intervals, and wherein at least some of said energy absorbing means are located in spaces in said assembly defined between said compartments.
 7. In an assembly for use in absorbing energy when the assembly or structure associated with the assembly is subjected to impact, the improvement comprising a plurality of flexible chambers positioned for receiving effects of said impact, a substantially non-compressible fluid normally located within said chambers, passage means extending from said chambers, fluid receiving means connected to said passage means whereby said chambers and said fluid receiving means are maintained in communication by said passage means, means for normally retaining at least a major portion of said fluid in said chambers in preference to said fluid receiving means, the force of an impact operating to transfer fluid through said passage means into said fluid receiving means, and whereby the fluid transferred is moved back to said chambers when said force is removed.
 8. An assembly in accordance with claim 7 wherein the assembly is associated with a structure comprising protective apparel, and including sizing means associated with the structure. 